Auger-bit



(No Model.) j I V 'T. WOOD & J. MORRIS. AUGER BIT. No. 254,184. Patented Feb. 28,1882.

N. PETERS, Piwlo-Lilhagmphan Wuningmn, 11c.

UNITED STATES PATENT OFFICE.

THOMAS WOOD AND JAMES MORRIS, OF BIRMINGHAM, CONNECTICUT.

AUG ER-BIT.

SPECIFICATION forming part of Letters Patent No. 254,184, dated February 28, 1882.

' Application filed July 18, 1881. (No model.)

.To all whom it may concern:

Be it-known that we, THOMAS W001) and JAMES MoRRis, of Birmingham, in the county of New Haven, in the State of Connecticut, have invented a certain new and useful Improvement in Boring-Bits, of which the following isa description, reference being had to the accompanying drawings, where- Figure l is a view of a boring-bit constructed in accordance with our improvement. Fig. 2 is'a detail view of the steel point or head of the bit before it is united to the malleable iron body. Fig. 3 is atop view of same.

The improvement consists in a boring-bit having a body of iron cast to shape, (subsequently malleableized,) and thecutting-point of steel firmly and durably united to the body in the process of casting, whereby the manufacture of boring-bits is greatly cheapened without sacrifice of efficiency.

The common process of manufacturing steel boring-bits is to take a square bar of steel of suitable size and length, and by common processes of heating, forging and the like flatten that portion of the bar which afterward becomes a screw, make the bar round-for a considerable space above such flattened portion, form a square tapering part at the upper end of the bar, twist the flattened portion into the shape of a screw, form the cutting-point, and crimp the screw part into regularity, after which the forging is ready for grinding and polishing.

It is the object of our improvement to do away with the greater partot' these operations, utilizing the process of casting for producing all of the bit except the cutting-point, which we make separately of steel by drop-forging or the like, and durably unite it to the body of the bit by the same'process of casting which produces that body.

The letter a in the drawings denotes the cast body of the boring-bit, and b the steel point. This steel point is formed in a separate piece, as represented in Figs-2 and 3, is provided on the bottom with a tang, b, which extends up into the body a, and is also provided on the bottom with recesses or slots b, which the cast metal enters, increasing the strength of the junction. 7

Itywill be observed that thedi'ametric center of the screw part of the boring-bit is larger than is common. This feature has two objects: first, to receive the tang b, and second, to diminish the size of the chipway, as well as to increase the strength of the body.

In the making of onrimproved bit a matrix is formed or used in the mold, covering the entire bit, including the point. Then, the pattern being withdrawn, (in case the pattern is used,) one of the cutting-points is put in its proper place in the matrix, and the body of the bit is cast, after which the bit is ready for the' subsequent operations of malleableizing,

grinding, polishing and tempering.

We claim as our invention A boring-bit having a cast-iron body and a steel point welded or fused thereto, all substantially as described, and for the purpose set forth.

a THOMAS WOOD. JAMES MORRIS, Witnesses:

O. L. BURDETT, G. M. SMITH. 

